Methods of bonding metal surfaces, and components therefor

ABSTRACT

The bonding of steel locating hinge washers to a hinge assembly to facilitate doors-off/door-on processing through an automotive trim shop. The adhesive bonding system cures during the cathodic electro-cost primer bake cycle. The adhesive maintains an intimate, positive contact with both metal surfaces ensuring adequate bonding performance and maximized bonding surface area during a defined heat or bake cycle.

[0001] The present patent application is claims priority from U.S.Provisional Patent Application Serial No. 60/244,998 filed Nov. 1, 2000,and is a divisional application of U.S. patent application Ser. No.10/039,722 filed Oct. 24, 2001 in which a Petition to Make Specialbecause of Actual Infringement was granted May 15, 2002.

[0002] The present invention relates generally to a method of bondingmetal objects in place to facilitate assembly operations, and componentsused in such a method. More particularly, the present invention relatesto a unique process of bonding in place metal objects, at least one ofsaid objects having pre-applied thereto an adhesive epoxy film or tape,and components used in such a process.

BACKGROUND OF THE INVENTION

[0003] In the past, many techniques have been tried to make assemblyoperations, especially in automotive manufacture, more efficient. Thishas been especially true with respect to the locating of hinge washersin the door hinge assembly processes of automotive vehicles.

[0004] The techniques which have been tried in the past are inaccurate,expensive, complicated, cumbersome, slow, and subject to frequentmalfunction.

[0005] It is a desideratum of the present invention to provide a novelprocess for bonding metal objects in place, and components used in suchprocess, which avoid the animadversions of the prior art techniques.

SUMMARY OF THE INVENTION

[0006] The present invention provides a washer device, comprising: ametal washer; a heat-curable adhesive bonding composition pre-applied toa first major surface of said metal washer; and said heat-curableadhesive bonding composition being capable of being cured to bond saidfirst major surface of said metal washer to an external metal substratewhen first major surface of said metal washer with said pre-appliedheat-curable adhesive bonding composition is brought into intimatecontact with said external metal substrate and is subjected to apredetermined heating until said pre-applied heat-curable adhesivecomposition cures to bond said first major surface of said metal washerand said external metal substrate together.

[0007] The present invention also provides a method of bonding a firstmetallic object to a second metallic object, comprising the steps of:applying a heat-curable adhesive bonding composition to a predeterminedpercentage of a predetermined metallic surface of said first metallicobject; bringing said heat-curable adhesive bonding composition appliedto said predetermined metallic surface said first metallic object intointimate contact with a predetermined metallic surface of said secondmetallic object; and while said intimate contact is maintained,subjecting said applied heat-curable adhesive bonding composition toheat until said adhesive composition cures to bond said predeterminedmetallic surfaces together.

[0008] The present invention further provides a fabricated tapeassembly, comprising: a release paper backing member; a film ofstructural epoxy adhesive applied to said release paper backing member;said film of structural epoxy adhesive being cut or perforated into aseries of adhesive annuli; said tape assembly being cut or perforatedinto a series of square tape sections; and each said square tape sectioncontaining a predetermined and pre-arranged array of said adhesiveannuli.

[0009] The present invention also provides a tray device which serves asa shipping tray and an assembly fixture to align a fabricated tapeassembly for washers, comprising: a main tray member divided into apredetermined number of square tray sections; two locating pins beingprovided in each said square section; and a plurality of posts affixedto said main tray member in each said square tray section.

[0010] The present invention further provides a method of bonding metalsurfaces, comprising the steps of applying an adhesive epoxy film ortape to a first metal surface of a first object, wherein said adhesiveepoxy film or tape is capable of withstanding production phosphatingsolutions, cathodic electro-coat primer solutions, and cathodicelectro-primer bake temperatures. The adhesive epoxy film or tapeapplied to the first object is then brought into intimate contact with asecond metal surface of a second object. Thereafter, the first metalsurface, the adhesive epoxy film or tape, and the second metal surfaceare subjected to cathodic electro-coat baking until the adhesive epoxyfilm or tape cures to bond the first and second metal surfaces together.

[0011] An object of the present invention is to provide a method ofbonding as described hereinabove by preparing a die-cut cast epoxy filmor tape on a release paper backing which is formed into predeterminedshapes in accordance with the first metal surface to be bonded.

[0012] Another object of the present invention is to provide a method asdescribed hereinabove which utilizes a high strength, heat cure,pre-applied, low tack, cast structural epoxy film or tape.

[0013] Yet a further object of the invention is to provide such anadhesive epoxy film or tape at a defined thickness and shape which ismost efficient for the bonding of metal substrates as an assembly aid topost processing.

[0014] Another object of the invention is to provide such a method asdescribed hereinabove for use in the bonding of steel locating hingewashers to the hinge assembly, to facilitate doors-off, doors-onprocessing through the trim shop and automotive assembly.

[0015] Yet a further object is to provide a method as describedhereinabove wherein the adhesive epoxy cures during the cathodicelectro-coat primer bake in assembly.

[0016] These and other objects, advantages and features of the presentinvention will become apparent to those persons skilled in this area oftechnology and to others when reading the detailed description set forthhereinbelow in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING

[0017]FIG. 1 is a top plan view of a novel shipping/assembly fixturetray of the present invention having assembled thereon a plurality ofmetal washers on top of adhesive tape.

[0018]FIG. 2 depicts a cross-sectional drawing illustrating the assemblyprocess for bringing the metal objects into intimate contact with eachother prior to bonding.

DETAILED DESCRIPTION OF SOME PREFERRED EMBODIMENTS OF THE PRESENTINVENTION

[0019] A first preferred embodiment of the present invention will now bedescribed.

[0020] First, there is fabricated tape comprising a backing or releasepaper 1 having applied thereto a film of structural epoxy adhesive. Forexample, the release paper 1 may preferably, but not necessarily,constitute treated polyethylene coated kraft paper. Furthermore, theadhesive epoxy may preferably, but not necessarily, constitute astructural adhesive supplied by 3M Corporation which is designatedAF-126(0.08 wt).

[0021] The tape assemblage of the release paper 1 with its structuraladhesive film thereon is then die cut into predetermined shapes andpredetermined dimensions. For example, such an assemblage may be cut orperforated into a series of adhesive annuli 2, with a plurality of saidadhesive annuli 2 in a predetermined perforated section of such tapeassemblage. For example, the tape assemblage may be cut or perforatedinto a series of square sections 3, 4, 5 or 6, with each such squaresection 3,4,5 or 6 containing a three-by-three array of nine suchadhesive annuli 2.

[0022] Four of such sections 3, 4, 5 and 6, each containing athree-by-three array of nine adhesive annuli 2, are placed in ashipping/assembly fixture tray 11 as illustrated in FIG. 1. Each squaresection 3, 4, 5 or 6 is placed on the two associated locating pins 7 and8 and nine posts 12 of the tray 11 with the adhesive annuli 2 of thetape assemblage facing upwardly.

[0023] A plurality of metal washers 9 which are countersunk on one side10 thereof are fabricated. The tray 11 serves as a shipping tray as wellas an assembly fixture to align the die cut tape for the washers 9. Foreach square section 3, 4, 5 and 6 in the shipping/assembly fixture tray11, there are placed nine such countersunk washers 9 with thecountersunk surface 10 abutting an associated epoxy adhesive annulus 2.

[0024] The shipping/assembly tray is provided with a plurality of maleprotruding members or posts 12 upon which the release paper 1 with theadhesive annuli 2 are placed, and on top of which there are placed thewashers 9.

[0025] The shipping/assembly tray 11 as depicted in FIG. 1 is then sentto the automotive assembly plants. A typical application includes thebonding of steel locating hinge washers 9 in the hinge assembly tofacilitate doors-off, doors-on processing through the trim shop.

[0026] When each washer 9 is removed from the tray 11, the adhesiveannulus 2 adheres to the countersunk side 10 of the washer 9 due to thetackiness of the adhesive annulus 2.

[0027] Each washer 9 is placed in a sandwich-like relation between twoportions 13 and 14 of the hinge assembly and maintained in intimatecontact therewith by way of a threaded bolt 15.

[0028] During the heat cure cycle, the adhesive annulus 2 is maintainedin intimate, positive contact with both of the metal surfaces beingbonded, to insure adequate bonding performance and maximize bond surfacearea. The epoxy annulus 2 has predetermined dimensions to be concentricwith the washer 9, but not coterminous therewith. Predetermined annularspaces 16 and 17 are provided within which the epoxy adhesive may spreadwithout running over the edges of the washer 9, and yet ensuring anadequate bonding performance.

[0029] The adhesive epoxy material is suitable for applications bondingmetal surfaces, such as galvanized, galvanneal, and cold rolled steel,which may be coated with metal forming lubricants. This special adhesivewithstands production phosphating solutions, cathodic electro-primersolutions, and cathodic electro-primer bake temperatures.

[0030] After the adhesive cures during the cathodic electro-primer bakeand assembly, the hinge portions 13 and 14 can be disassembled leavingthe steel locating hinge washer 9 in place for later assembly.

[0031] The method includes all variations wherein application of theepoxy adhesive material can be at any point prior to the cathodicelectro-coat bake in the body shop area of assembly or in the stampingplant.

[0032] Preferably, but not necessarily, the epoxy adhesive is notresistance weld through capable.

[0033] Various modifications of the process and the components thereforeas described hereinabove are contemplated by the present invention.Therefore, while there have been set forth some preferred embodiments ofthe present invention, it should be understood that the presentinvention is not to be limited or restricted to the particularembodiments described in detail hereinabove which have been set forthfor illustrative purposes only

1. A method of bonding a first metallic object to a second metallicobject, comprising the steps of: applying a heat-curable adhesivebonding composition to a predetermined percentage of a predeterminedmetallic surface of said first metallic object; bringing saidheat-curable adhesive bonding composition applied to said predeterminedmetallic surface said first metallic object into intimate contact with apredetermined metallic surface of said second metallic object; and whilesaid intimate contact is maintained, subjecting said appliedheat-curable adhesive bonding composition to heat until said adhesivecomposition cures to bond said predetermined metallic surfaces together.2. The method according to claim 1 , wherein: said heating isaccomplished by subjecting said metallic objects and said adhesivecomposition to cathodic electro-coat primer baking until said adhesivecomposition cures to bond said predetermined metallic surfaces together.3. The method according to claim 1, wherein: said adhesive bondingcomposition maintains an intimate positive contact with saidpredetermined metallic surfaces during a predetermined heat cycle. 4.The method according to claim 2, wherein: said adhesive bondingcomposition maintains an intimate positive contact with saidpredetermined metallic surfaces during a predetermined heat cycle.
 5. Amethod of bonding metal surfaces, comprising the steps of: applying anadhesive epoxy film or tape to a first metal surface of a first object;said adhesive epoxy film- or tape is capable of withstanding productionphosphating solutions, cathodic electro-coat primer solutions, and/orcathodic electroprimer bake temperatures; bringing said adhesive epoxyfilm or tape applied to said first object into intimate contact with asecond metal surface of a second object; and subjecting said first metalsurface, said adhesive epoxy film or tape, and said second metal surfaceto cathodic electro-coat baking until said adhesive epoxy film or tapecures to bond said first and second metal surfaces together.
 6. Themethod according to claim 5, including the step of: preparing a die-cutcast epoxy film or tape on a release paper backing which is formed intopredetermined shapes in accordance with said first metal surface to bebonded.
 7. The method according to claim 5, including: using a highstrength, heat-curable, pre-applied, low tack, cast structural epoxyfilm or tape.
 8. The method according to claim 6, including: using ahigh strength, heat-curable, pre-applied, low tack, cast structuralepoxy film or tape.
 9. The method according to claim 5, including:providing said adhesive epoxy film or tape at a defined thickness andshape which is efficient for the bonding of metal substrates as anassembly aid to post processing.
 10. The method according to claim 6,including: providing said adhesive epoxy film or tape at a definedthickness and shape which is efficient for the bonding of metalsubstrates as an assembly aid to post processing.
 11. The methodaccording to claim 7, including: providing said adhesive epoxy film ortape at a defined thickness and shape which is efficient for the bondingof metal substrates as an assembly aid to post processing.
 12. Themethod according to claim 8, including: providing said adhesive epoxyfilm or tape at a defined thickness and shape which is efficient for thebonding of metal substrates as an assembly aid to post processing. 13.The method according to claim 5, wherein: said first object is a washer;said second object is a portion of a hinge assembly; and said method isused in the bonding of said washer to said hinge assembly, to facilitatedoors-off, doors-on processing through a trim shop and automotiveassembly.
 14. The method according to claim 6, wherein: said firstobject is a washer; said second object is a portion of a hinge assembly;and said method is used in the bonding of said washer to said hingeassembly, to facilitate doors-off, doors-on processing through a trimshop and automotive assembly.
 15. The method according to claim 7,wherein: said first object is a washer; said second object is a portionof a hinge assembly; and said method is used in the bonding of saidwasher to said hinge assembly, to facilitate doors-off, doors-onprocessing through a trim shop and automotive assembly.
 16. The methodaccording to claim 8, wherein: said first object is a washer; saidsecond object is a portion of a hinge assembly; and said method is usedin the bonding of said washer to said hinge assembly, to facilitatedoors-off, doors-on processing through a trim shop and automotiveassembly.
 17. The method according to claim 9, wherein: said firstobject is a washer; said second object is a portion of a hinge assembly;and said method is used in the bonding of said washer to said hingeassembly, to facilitate doors-off, doors-on processing through a trimshop and automotive assembly.
 18. The method according to claim 10,wherein: said first object is a washer; said second object is a portionof a hinge assembly; and said method is used in the bonding of saidwasher to said hinge assembly, to facilitate doors-off, doors-onprocessing through a trim shop and automotive assembly.
 19. The methodaccording to claim 11, wherein: said first object is a washer; saidsecond object is a portion of a hinge assembly; and said method is usedin the bonding of said washer to said hinge assembly, to facilitatedoors-off, doors-on processing through a trim shop and automotiveassembly.
 20. The method according to claim 12, wherein: said firstobject is a washer; said second object is a portion of a hinge assembly;and said method is used in the bonding of said washer to said hingeassembly, to facilitate doors-off, doors-on processing through a trimshop and automotive assembly.